The results of an investigation into an E.coli outbreak linked to Dunsyre Blue leave as many questions as answers, says Jane Bradley
IT is an imposing document - and one which should have spelled the end to the row over an E.coli outbreak which tragically killed a three-year-old girl and hospitalised 17 others.
But while the 101-page report published by Health Protection Scotland (HPS) earlier this week gives a fascinating insight into how authorities deal with such an outbreak, it has thrown up more questions than answers from the cheesemaker whose products have been deemed responsible.
It is a case which I have followed closely, as a consumer journalist - and one which has proved increasingly complicated at every turn.
The Incident Management Team report into last summer’s outbreak insists that Dunsyre Blue, an artisan blue cheese made in Lanark, was the source of the bacteria, which infected a total of 26 people.
But Humphrey Errington, founder of Errington Cheeses, continues to insist that his product is not linked to the illness - which causes a range of unpleasant symptoms including diarrhea, stomach cramps and kidney failure - and has vowed he will take a legal case to the highest level to clear his name. He has consistently claimed that independent testing of his cheeses has shown no presence of the bacteria.
He has been supported by a string of big names in the Scottish food world, including food writer Joanna Blythman, who launched a crowdfunding campaign to pay his legal bills, generating £34,000 from well-wishers.
However, this week’s report was not in his favour, insisting that “extensive investigations” had concluded that the source of the outbreak was the consumption of Dunsyre Blue.
Working out how this outbreak could have occurred is the most complicated jigsaw puzzle.
The first eight cases of the illness were reported on 21 July. The initial victims were resident across five NHS boards in Scotland.
The HPS report shows that of the 26 people who were eventually infected, 21 lived in Scotland, while three were resident in England and another from Ireland, but had all visited Scotland in the weeks preceding their infection. There was only one case of a victim who was from England and had not visited Scotland during the incubation period.
One of those affected was a three-year-old girl from Dunbartonshire, who tragically died.
Those affected were given a comprehensive food diary to complete for the week and a half before they became ill. Yet, to add extra confusion to the case, unlike more common types of food poisoning, E.coli has an incubation period of up to ten days, making it hard to narrow down a common ingredient which people may have consumed.
Dunsyre Blue was pinpointed as a possible cause fairly early on.
It turned out that a total of 15 of the 24 primary cases were known to have consumed the cheese; another two people had eaten blue cheese from a shop selling Dunsyre Blue but were unable to recall the type of cheese, and one person with the illness had attended a function at which Dunsyre Blue was served but did not recall eating it.
Of the remaining six “primary cases” - people who were infected from eating something containing E.coli bacteria - one case had eaten blue cheese but it was unable to be determined what type of blue cheese or where it had been purchased from; another reported eating blue cheese but not Dunsyre Blue and for one case there was very limited information available. Two of the victims were understood to be workers at a hotel or restaurant where they had eaten blue cheese, while many others had eaten at various places which serve the cheese.
None of the samples taken from hotels and restaurants by HPS tested positive for E.coli, according to the report - however, they were taken more than a month after the cheese was eaten by cases, so the block of cheese eaten by the victims was no longer available for testing.
However, by the time the incident team was stood down on 26 October, investigators had come to the conclusion that Dunsyre Blue was common to enough of the victims that it was a likely cause.
Then, on 15 September, another cluster of cases emerged. Three children who all attended the same playgroup in Carnoustie were struck down with the illness. Soon afterwards, two more cases were reported - all people who had acquired their infection from close contact with the young victims of the illness.
These new cases occurred six weeks after the first outbreak had appeared to be over.
But the report showed that investigators were unable - and are still unable - to establish how Dunsyre Blue cheese could be linked to these cases.
Puzzlingly, neither the children themselves, the care givers at the nursery, nor their parents, reported eating Dunsyre Blue during the time period in question. No other children or users of the playgroup tested positive for E.coli.
The only possible conclusion, the investigators said, was that an affected person unknown to the authorities who perhaps did not have severe symptoms and was using the same venue for some other reason than the playgroup, may have used the toilet and passed on the infection.
“What are the chances that some unknown person would have used the children’s toilets?” asked Errington. “They say it is the same outbreak, but none of these people had eaten Dunsyre Blue.”
The report stated that aside from the five cases associated with the childcare cluster and two cases who had consumed food from the same hotel, there were “no common links” between the remaining cases in terms of where people had eaten or visited.
The report said that of the two affected batches of Dunsyre Blue, 67 per cent and 71 per cent respectively of the supply direct from Errington Cheese Ltd was to Scottish businesses - hence why only one case occurred in England without any Scottish connection.
But Errington is not convinced. The report says that the HPS “considered a number of biologically plausible vehicles of infection” but Errington, who has finally been allowed to recommence production of his Lanark Blue cheese after six months with his factory mothballed - albeit under stricter milk testing regimes - insists that his cheese was victimised from the start.
“They decided the cheese was the cause and spent the next two months trying to prove it, rather than the other way around,” he claims.
His case is set to be heard by a sheriff in Lanark next month.
Whether Errington has a point, or whether the HPS report will be deemed to be right, remains to be seen. But what the report does reveal, is that pinpointing the cause of an outbreak is very difficult.